1. Field of the Invention
This invention relates to a continuous filter, and more specifically, to a continuous filter in which the amount of a slurry to be treated per unit filtration area is large and the squeezed cake can be discharged continuously.
2. Description of the Prior Art
An Oliver filter, a belt filter, etc. have previously been in widespread use as a continuous filter using a filtration medium such as filter cloth. These filters are of such a structure that slurry is fed on a continuously moving filter medium, and filtered while the slurry is moving on the filter medium, and the resulting filtration cake is scraped off from the filter medium. In this type of continous filter, the degree of pressurization or pressure reduction cannot be made high or in other words, the filtration rate is relatively slow. In addition, with this type of filters, filtration of fine particles is difficult, and in particular, they cannot be used for the filtration of a viscous liquid. Moreover, since these filters are of the open type, the solvent in the slurry is wasted into the atmosphere to pollute the working environment.
The filter press or a Buchner funnel used to be the type for fine particles, a viscous liquid, etc. but, have the defects that the operation is batchwise, and a high treating ability cannot be expected.
In principle, the filtration rate is inversely proportional to the thickness of the filter cake. It is desirable for the filter therefore to minimize the thickness of the cake and perform its filtration continuously instead of batchwise in the closed chamber.